1. Field of the Invention
The present invention relates to a mower unit comprising a mower deck including a plurality of rotary blades arranged side by side, and a mulching baffle having a vertical guide wall defining at least part of a boundary wall of a mulching chamber for each rotary blade, wherein the mulching baffle is detachably installed in the interior of the mower deck thereby to allow a mulching operation to be carried out. This mower unit is also applicable, with removal of the mulching baffle, to a mowing operation carried out in a side-discharging mode where grass clippings cut by the rotary blades are collected and discharged from a discharge outlet formed in the mower deck.
2. Description of the Related Art
A conventional mower unit which is convertible between a normal discharging mode and a mulching mode is known from U.S. Pat. No. 5,987,863 in which independent mulching chambers are formed for respective rotary blades by utilizing a sheet-metal mulching baffle.
Another conventional mower unit is known from U.S. Pat. No. 5,628,171 in which mulching chambers are formed for respective rotary blades by utilizing a hollow block-like mulching baffle, the adjacent mulching chambers being allowed to communicate with each other through small openings formed in boundary regions thereof.
The mulching baffle for allowing a mulching operation includes a vertical guide wall having a partially arcuate configuration extending along a locus of rotation of each rotary blade in plan view in order to retain and re-cut grass clippings in each mulching chamber for each rotary blade. Each of the mulching baffles disclosed in the above U.S. patents includes a vertical guide wall having an upright wall surface, as a result of which grass clippings cut and thrown up from growing grass will swirl and travel along a rectangular corner space defined by the vertical guide wall of the mulching baffle and a deck top plate. This may cause the grass clippings to adhere to or remain in the rectangular corner space to deteriorate a mulching performance depending on the type of grass, length of grass, amount of grass reaped per unit time, moist state of grass, etc.
Further, with the mower unit according to U.S. Pat. No. 5,628,171 noted above, since the adjacent mulching chambers communicate with each other through the small opening in the boundary region thereof, the grass clippings would flow from one to the other of the mulching chambers. This may cause a problem of deteriorating the mulching performance.